[Genetic surgery: results of a new technique (author's transl)]

New techniques for cleaving DNA molecules at precisely defined points, and for successful DNA-transformation of E. coli have allowed genetic engineers to ligate DNA fragments of all possible origins and to convert them into replicating molecules sustained within bacterial cells. For this purpose, typically, segments of eukaryotic DNA are linked to bacterial "vectors", in particular plasmids carring their own replication machinery. This procedure allows to study the genetic organization of eukaryotic DNA and to detect whether or not the eukaryotic genes will function in a foreign environment. Work has just been initiated aiming at the complementary procedure, i.e., at introducing prokaryotic or foreign eukaryotic genes into eukaryotic cells which may carry hereditary defects.